Solvay Sa

Thoi-Dai Chau

Alain Vandendoren

Kurt Allen

Hugo Walravens

David Jean Lucien Savary

Claude Breton

Joffrey Piet

A process for preparing sodium bicarbonate particles, comprising the steps of: (a) adding at least one alkali metal carbonate to an aqueous solution in order to form an aqueous composition; wherein the alkali metal carbonate comprises sodium carbonate and wherein the aqueous composition comprises at least one polycarboxylic acid and/or the salts thereof, in an amount of at least 200 ppm based on the weight of the aqueous composition; and (b) precipitating solid particles comprising sodium bicarbonate crystals and separating said sodium bicarbonate particles from the aqueous composition, in order to obtain sodium bicarbonate particles and an aqueous mother liquor.

Process for preparing sodium bicarbonate particles

A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising at least 2% sodium chloride and/or sodium sulfate by weight, a part of such stream (A) being generated by a sodium carbonate crystallizer, comprising: a) mixing the stream (A) with part of a stream (B) to produce a stream (C); b) bicarbonating the stream (C) with a gas (D) comprising COto produce an aqueous suspension (E) containing crystals (F) comprising sodium bicarbonate crystals; c) separating the aqueous suspension (E) to obtain crystals (F) comprising sodium bicarbonate crystals and an aqueous mother liquor (G); d) partly debicarbonating such liquor (G) and removing part of the water to obtain the stream (B) and an optional gas (H); e) recycling at least part of the stream (B) to step a); and f) removing the remainder of the stream (B) or part of the aqueous mother liquor (G) to be further processed.

Process for producing sodium bicarbonate

A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising sodium carbonate and an alkaline metal salt impurity at a concentration C(A), comprising: a) mixing the stream (A) with part of a stream (B), b) bicarbonating the resulting mixed stream with a gas comprising COto produce an aqueous suspension comprising sodium bicarbonate crystals (F), c) separating the sodium bicarbonate crystals (F) from the aqueous liquor (G), d) partly debicarbonating at least part of (G) and removing part of the water of (G) to obtain the stream (B) with the salt impurity at a concentration C(B), e) recycling part of the stream (B) to step a) so that the ratio of the concentrations C(B)/C(A) of the impurity is at least: 1.4, and f) removing the remainder (I) of the stream (B) or the remainder (J) of the liquor (G) to be further processed.

A process for the production of sodium carbonate and sodium bicarbonate out of trona, comprising crushing trona ore and dissolving it in a leaching tank containing a solution comprising sodium carbonate and sodium bicarbonate, and an additive selected from the group consisting of: phosphates, phospholipids, carboxylates, carboxilic acids, and combinations thereof, saturated in sodium bicarbonate, in order to produce solid particles suspended in a production solution comprising sodium carbonate, the solid particles containing insoluble impurities and at least 65% by weight of sodium bicarbonate. The solid particles are separated from the production solution containing sodium carbonate. At least part of the production solution containing sodium carbonate is taken out of the leaching tank.

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Bad Hoenningen, Germany

Thoi-Dai Chau